The alkylphenol anesthetic propofol is used in millions of surgical and noxious procedures annually. While the clinical use of propofol has swelled, mechanistic understanding of its many actions, on all levels, has lagged behind. In this proposal, we will deploy our photoactive alkylphenol analogues of propofol, azi-propofol-m (aziPm) and 2-propynloxymethoxy-5-trifluoromethyldiazirinylphenol (aziPm-click), in a tiered series of studies to reveal: the photoactive alkylphenol binding proteome using state-of-the-art mass spectrometry and enrichment methods (aim 1), the electro- physiological character of photoactive alkylphenols in discrete nuclei in brain slices (aim 2), and the in-vivo contribution o individual cells and networks to the hypnotic effects of alkylphenols. These latter studies will us fiberoptic laser stimulation of discrete regions of brain in live mice after systemic administratio of photoactive alkylphenols (aim 3). The three aims are integrated by their common prediction of molecular substrates arising from very different, complimentary and unbiased approaches. These studies will result in the identification of novel and plausible molecular substrates for alkylphenol action, which will serve as the basis for validation in subsequent proposals involving the construction of genetically altered animals. This collaborative project is ideally suited to integrate the neurobiological expertise of the Kelz lab with the electrophysiologic mastery of the Beck lab, and the biological chemistry prowess of the Eckenhoff and Dailey labs.